Urbal

Thank you @Mikdun - just as expected! I second this! Let's indeed stick to 42177 discussion as @Milan steered, but the sheer reason of why diff lock was put into a manual model, I believe does worth exploration for the reasons mentioned in my previous post. Lego Technic is a great prototyping tool, used by school (and not only) teams worldwide. Now, even if you decide to put it onto the shelf, there is nothing wrong in learning something from the original model, rather than saying 'who cares, it's just a 3D puzzle toy". Fully agree with @TeamThrifty that back in the days people spend more time rebuilding, and I must say the joy of creating something new and different, from existing elements is just unparalleled! The demand for that should be communicated to TLG. And as part of that, I'd like to re-iterate the importance of B-models - hence so much respect to somebody who managed to deliver B-model within days from official release, kudos to you sir, @M_longer

Ah sorry for the ambiguity: I had issues with PU Control+ XL motors suddenly dying, or only spinning back and not forward EDIT: both times they were replaced by TLG, but the hassle of reinstalling them within the frame, aghh... that's a pain in the butt!

@Mikdun just to be more specific - do you try to use central diff or diffs between wheels? I guess you meant the latter, seems that central diff effect in Lego cars is not so noticeable (especially in RC cars) - still the effect is there, and I tend to attribute 2 XL motors failures I had to their use in MOC without central diff. But I might be wrong here and XL motors might actually be delicate due to other reasons - but I've heard failure stories from others, and they were eventually discontinued... Anyhow don't want to speculate on this one, as XL motors conundrum is a whole different story :)

Well, I guess drifting implies locked rear diff, or did you mean that even being unlocked you have a good drifting car? Thank you for the drifting car recommendation, but I'm keen to have a more versatile manual offroader experience, don't plan to embrace buggy motor/Buwizz territory :)

Guys, with all due respect there is too much generalisation in the replies, and no, you won’t upset me in the slightest :) I know what to expect from 1:10 scale model - they could be perfectly playable for a kid (or parent :)), and 42110 Defender was just that (especially with the revised gearbox) - unlike bigger 1:8 supercar brothers with their minimal clearance and no HoG. I think 42177 was praised here for the lack of gearbox not least because of the improved reliability comparing to 42110 Defender - which doesn’t make sense if you only care about the looks on the shelf… Anyhow, I believe that ‘play’ is important thing for manual Lego off-roaders line, represented by 42069, 42110 and now 42177, all designed by Milan, and unofficially sitting underneath supercar range as functionally packed yet approachable sibling to a more aesthetics focused ‘supercar’. Ok, I do appreciate that it could be only my humble understanding of Lego technic offroader/supercar lineups. But my question is there, and I believe it is legit as any other question addressing user experience with the model - don’t think there is anything wrong with it :) My take on this is the following: if ride resistance is there with the diffs locked, then it would be a good showcase for differential as it is - so that the one (especially younger user) can learn a thing or two about the purpose of diffs while rolling the model over flat grippy surface vs a blanket (the latter should minimise the effect and be almost like off-road imitation with free wheel skidding caused by windup). As many things in Lego Technic cars are shown indirectly - take fake engine pistons for example, they are fake for an obvious reason being moved by the wheels, not vice versa as they are in real life, but it shows the concept of drivetrain. Locked diffs could be similar reverse-engineered demonstration to appreciate the effect of open diffs for somebody who took them as granted. Now, the key word here is ‘could’ - hence my question to check the reality EDIT: Thank you @Mikdun, that's the feedback I was looking for... Sure thing when rolling straight there is no difference. What I'm curious is how big the circle/curve shold be to feel the resistance. Also, may I ask whether your experience based on same size/weight vehicles as 42177 (roughly 1:10 scale)?

Sorry but would be great to hear real life experience, let’s not speculate on what else can be shown or what is fashionable in MOC, or Chinese Lego… The question is: Does locked diff make model rolling noticeably harder or drivetrain low tolerances (and I can also think tire skidding) mitigate the wind-up effect?

One thing that wasn’t mentioned at all by any reviewer so far - how does it feel to roll the Gwagen with central/both diffs locked, any resistance windup effect?… Any observations are welcome, as I still not sure what to expect with Lego wheel traction, and hence whether it makes sense to include locking diffs into manual models

Yep, live axle with a locking diff is placed instead of the gearbox. Actually I always questioned the gearbox location in Defender... So all things considered it might be the right move. The question I have is whether the model delivers a better design-function balance than Defender. I guess we need some quality reviews of a more experienced folks to answer that.

@StudWorks well, that's the thing - I assume that having the diffs locked would stiff the rolling on the surfaces with good traction, while keeping it on a blanket... But you need to be quite focused to feel the difference. Hence my question to the community on the obvious solution to demonstrate torque distribution (i.e. without motion sensor on every wheel). Anyone?

@Ngoc NguyenI agree, Hi-LO will do the job just fine for an offroader model, I much prefer locking diffs in it... ideally with some kind of a way to see them working (other than obvious rolling resistance). Newbie here, so didn't come up with the idea, so if more experience comrads had a thought on what kind of mechanism might show the actual wheel speed/torque distribution - please do share! I think it might be much more satisfying feature than fake engine ;)

@dabo looks like it is indeed Defender model 1:10 scale replacement, with very similar dimensions (Brick Fanatics mentioned negligible 1cm difference) So, having watched the aforementioned review along with Lego official materials.... comparing to Defender we will be missing 4 speed gearbox, instead we are given locking central and rear diff locks. Honestly, I think that this is the spec Defender should have had with its smaller(ish) 2-door footprint, there was no real need for the gearbox... This time however, I have a feeling that while Defender was almost overpacked with features), Gwagen might feel be a bit hollow - not much use of the increased 4-door chassis with the actual gearbox removed, and less parts for the B-models... Thoughts?

Hey @jb70 great to see that you are still revisiting venerable Defender set, kudos to you! Especially grateful for addressing Ackerman geometry, one of my early feedback more than a year ago! You probably sick and tired from Defender already, but may I ask you - did you consider compacting the drivetrain/gearbox in a way to make the whole layout more realistic, and thus emptying the trunk? I noted that @gyenesvi had compacted the gearbox in his MOC-81354 (saving its characteristics of 4+2 gears), interestingly he referenced your model as an inspiration :) Basically it should fit into the Defender frame if my stud calculation is correct. In my mind, that would be a dream 42110. I almost ready to pay for it, as sadly don't have time to finish it myself - as the existing layout (linkage to gearbox in the trunk and back) really bugs me! With a proper layout of engine->gearbox->transfer box with diff, it would be a staple in Technic modelling, especially providing the 1:10 scale!

Hey @kenkwong, great work and to me internals actually do look quite more intriguing than the already impressive exterior... May I ask about the orange switching gear - seems to be a central diff lock? I was considering this mod as well, would be great to hear whether you feel any resistance while rolling Defender with central diff locked? Also, I always had an issue with gearbox in the trunk. Seems that this has been addressed as well and you moved it to the central part - would be great to see some pictures of the drivetrain. Otherwise great work, thanks for posting!

To be honest, I don't think we need more powerful motors - 2 XLs are enough for a large model. I think we need more building blocks (gears and clutches) to make the builds more efficient, especially off-road vehicles. The bottom line for me is that Technic is a prototyping tool, not meant to compete with performance RC models. But then, a prototype must demonstrate something (slow/fast, grip/slip etc.) - i.e. show engineering concept in practice. And this is where Technic toolbox could be a bit more versatile so that builders could create more realistic functions - in my case a gearbox that is meaningful and efficient, not that taxing for power/torque, and differentials that are easy to lock - so the axle is not that huge. I was really hoping to see the new LSD detail in 42129, or a mix of hardware and software implementation of it, but apparently not yet... Anyhow, let's stay positive and check out the actual reviews

u118224, don't want to divert the main topic too much, but thanks for chiming in - these are good points indeed. TLG motors being not that powerful, and body detail being very taxing on model's weight, plus lack of specific details (e.g. we still missing 24 teeth clutch gear - we only have 16 and 20 teeth available...) makes it really hard to deliver something detailed and functional at the same time... Still, dealing with power/weight balance makes Technic build challenging and well,.. interesting hobby I suppose! Finding the right balance moves some MoC into engineering art territory IMHO. Back to 42129 - agree, it's good to see remotely lockable diffs, and they will certainly help the model to climb - as axles articulation is frankly not that impressive. Let's wait for the reviews and see whether geometry is an issue (I believe it might be stuck here and there due to massive axles and long wheel base). Anyway, I see 42129 as a step in the right direction - delivering more remote functions and striping out model body a bit (and, yes, i like Technic old school skeleton bodies) - I'm glad Zetros presented as a trial truck, doesn't have any crane arms like Arocs, and thus is lighter!

Based on Milan's presentation, I think it'd be safe to assume that 1) there is no gearbox and Zetros is geared quite low (as was shown in the video) 2) there is no self-locking differential - and both central and rear differentials are lockable on demand, but not automatically... Still not bad in my opinion, but truck's geometry leaves quite a lot to be desired. However, I'm glad that TLG finally got the guts to release a model with lockable diffs. Self-lockable is probably a bit too much to expect considering current state of TLG designs... But the dream is still there: to have an offroader RC model with realistic chassis, that would have 2 speeds (capable to climb the obstacles OR fast enough if need be) with lockable diffs (as realistic chassis would most likely require them).

Hm, don't know guys, in my case v1.3 doesn't rub at all. Here is the image of the steering arm: https://imgur.com/a/DCDypea BUT, I must admit the other minor issue that does exist: if you hold Defender in your hand and try to turn the front wheels not with HoG, but with your hand, then there is a bit of friction of the steering gears in the front (24t and 8t) - if you slightly press the wheel up they do connect and prevent steering. However, on the ground it steers fine, no unnecessary friction. Hope it helps

Based on @jb70 V1.3 front steering rack I managed to integrate radiator fan under the hood. I think it's quite nice modification as gives the one an opportunity to see how reverse gear works (i.e. that the shaft rotation is correct). Plus I made an engine 4 piston instead of six, as a) I believe it's true to most Defenders being 4-cyl diesel off-roaders b) actually makes engine movement (firing order) correct and its sound smooth and balanced.

Thanks for the link! I also found other interesting materials to educate myself more on the Ackermann geometry subject, probably the most comprehensive and digestible is this one: and must admit that I was wrong in my suspicions and @jb70 steering solution is indeed pro Ackermann! However it's not visible to me and I don't see the wheel angle different in practice - it's so much wobble in the steering mechanism so it's hard to appreciate the effect. Please share if you experience differs. @tomek9210 sorry for the confusion, the picture I shared was about issue on building Ackermann without moving the tie rod to the front of the axle, i.e. I was trying to build Ackermann based on V.1.2 and found that there is a bit of a friction with this setup (between the already offset rim and the steering rod), so you either need to change the rims to standard ones without offset or move the tie rod (as was done in V1.3). Hope it makes sense and no confusion here:)

@jb70 I have built V1.3 of PUMLR and still believe that what we have there is a slight Anti-Ackerman geometry. Here is a quick snapshot of different types and to me it looks like anti/reverse version I believe the challenge with Ackerman geometry is there because of the Defender rims, when you put a slight offset it touches the rim a bit and that causes a light friction. Here is the photo to depict the issue. For now I will return to V1.2 with drivetrain adjustments, as it turns better than V1.3.

@jb70 Thanks for a quick reply on the body stiffness, sounds great! Now, I have modelled suggested Ackermann setup with available parts (and removal of one shock absorber on each , and it looked to me as Anti-Ackermann geometry used for racing cars, not offroad ones. Sorry if I'm saying nonsense, but to me it looks like that and steering is actually quite hard due to resistance of the outer wheel... Again, I would hate to add some noise, but appreciate if you could double check. Thanks! I've shared the photo of my PoC here Update: I believe anti (or reversed) Ackermann effect is there because of 1 stud offset is done into the wheel, not out. The latter is not possible though due to special Defender rims... Update2: I think the catch is that I put suggested geometry in the V1.2 setup with steering rack behind the front axle - apparently changing the axle positing and steering rods would change Anti- to just Ackermann :)

Many thanks for being honoured with your mentioning! I was actually trying to find a solution for Ackermann steering geometry behind the front axle - as I believe it is true to the new Defender - but also didn't find the one. However, just after your post I have found out that old Defenders used to have steering box and links in front of the axle! Hence steering guards are so popular for offroading Defenders. So your solution is very reminiscent to old Defs! I'm ordering a longer steering rack and anticipating an enjoyable V1.3 build, again appreciate all your efforts to pull all the great changes together! P.S. Quick question on the removable body (which is again quite a reference to old body-on-chassis Defs! ;) - did you find any significant impact on overall structural rigidity of the vehicle?

Leewan, many thanks for elaborated explanation! Works great!

Leewan, thanks for sharing your findings! I definitely like jb70 Pimped version much, much better than the original! Indeed,16T better for central diff otherwise drivetrain is too fast and it's hard to move the vehicle. However, I didn't find an easy way to swap for 24T/8T for engine at steps 3-4 of DNR/HiLo mode as suggested. Can you please provide a bit more details? I put 8T at the crankshaft and then was trying to put 24T using grey 4L axle instead of brown 3L - but there is not enough space due to the black T-shape holding steering axle. Appreciate your guidance, thanks!

Had recently the same issue with 20T gear in both 42099 and 42110 sets. What is the way to replace them?